The present invention relates to an actuating drive for moving a movable furniture part, including an actuating arm pivotally mounted about a pivoting axis for moving the movable furniture part, a spring device for applying a force onto the actuating arm, and a transmission mechanism for transmitting a force of the spring device onto the actuating arm. The transmission mechanism includes an actuating portion movement-coupled to the actuating arm, a setting contour, and a pressure portion pressurized by the spring device. The pressure portion is in the form of a rotatably mounted pressure roller which can run along the setting contour upon a movement of the actuating arm, and the setting contour is arranged between the actuating portion and the pressure roller.
The invention further relates to an arrangement having a movable furniture part and an actuating drive of the kind to be described.
Such an actuating drive is shown, for example, in DE 10 2006 014 493 A1. Here, a pivotally mounted actuating arm is rotatably mounted by a setting contour arranged on the actuating arm and a pressure portion in the form of a pressure roller abutting the setting contour. The setting contour of the actuating arm is formed by the material thickness of the actuating arm and additionally by disc portions arranged on both sides of the actuating arm (disc portions 30, 31 in FIG. 4). As a result of this three-part construction, the contact surface for the pressure roller is enlarged and thus the arising forces can be distributed over an enlarged area.
Usually, the setting contours of such actuating drives are produced by precision blanking or fine blanking, respectively. In other words, the setting contours are produced by a manufacturing process in which during a working operation, workpieces can be produced having a precise contour with smooth and rectangular cutting edges. An advantage of this technology in comparison with a usual punch technique is that by way of the achieved clean cut, a high surface quality can be attained so that a laborious post-treatment of the setting contours (for example polishing) can be omitted. A smooth surface of the setting contour is namely a necessary requirement because possible irregularities are negatively noticed by a user when opening and closing the movable furniture part. A disadvantage of the precision blanking is, however, the fact that this manufacturing process is relatively costly and only a low number of cutting cycles are permitted in serial production.
A further disadvantage of the known designs of setting contours is the fact that the running surface provided for the contact with the pressure roller is determined by the material thickness of the setting contour. Accordingly, relatively high material thicknesses must be provided in order for a sufficient stable abutting surface, which is partially pressurized by the spring device with very high pre-stressing forces, for the pressure roller to be obtained.
WO 2004/104339 A1 shows an actuating mechanism for furniture flaps, in which a pivotally mounted actuating arm on the end forming the setting contour has a surface which runs perpendicularly to the pivoting axis of the actuating arm. With relation to the pivoting axis, a bulge axially protrudes from this surface, and the bulge extends along the setting contour. Moreover, a guide shoe with a groove is provided which accommodates the bulge and which is guided along the bulge. Thus, the guide shoe flatly abuts against the bulge in order to avoid punctual contacts or line contacts with high surface pressure. However, the surface quality of the bulge does practically not matter at all, because possible irregularities of the bulge are compensated for by the flat contact of the guide shoe and do not have any influence on the movement behavior of the actuating arm.